The ballet pupil Camilla Favier makes for a quick success and falls for the author Jean Mayol. She discovers a love letter to him from a rich married woman and is devastated. In revenge she reveals the secret love story for the cuckolded husband and his guests at a big party. Later she finds a new love message from the wayward wife and brings it to the husband, who gets furious, grabs a pistol and incites the climax of the story.

Ditte is born out of wedlock and lives as a young girl with her old beloved grandmother. As an illegitimate child she is teased in school and more than anything in the world she wants a father. When steady - utterly reliable - herring dealer Lars Petter shows up and tells her that he is marrying Ditte's mother, the little girl is very happy. Now Ditte must take care of three new sisters and brothers but gets nothing but complaints from her ungrateful, selfish mother. But the little girl finds consolation and support in both her sisters and brothers and Lars Petter.

1950 film

A woman is found strangled in her shop. Shortly after, another murder is committed. Perhaps the most terrifying is that the both girls' name is Sonja. The police is convinced it's the same killer and at each scene is heard a woman singing the same song. A song which is soon dubbed the 'murder melody.'